Etching machine



Dec. 6, 1927.

F. T. POWERS ETCHING MACHINE Filed Dec. 23, 1926 IIIJIIJIII.

I NVENTOR I Patented Dec. 6, 1927.

' UNITED STAT-ES FRANK r. rownn's, or DOUGLASION, NEW

ETCHING. MACHINE.

- Application fi1ed IDeeember 23, 1926. Serial No., 156,650.

My invention relatesi'to apparatus used for etchingarticles of various kinds but more particularly for the etching of metal Y plates used in printing, such as, are prepared forthe printing process by photo-mechanical-chemical meansand areknown as halftone plates'or line cuts.

One object of my invention is to obviate the necessity of the etcher reaching into or stooping over the etching tank in which the process of etching photo-mechanical printing plates is commonly carried on.

"Another object is to provide a more con venient rest or carrier for the plate so as to lessen the-amount of handling of the plate by the etcher, and to permit the examination of the plate during the process of etching without the necessity of the etchertouching the plate or of'gett-ing any of the etching fluid on the'handsof the etcher. '1 laccolnplish these and other desirable results, which will become apparent to one skilled in the art ofetc'hing plates of the character described upon; a-study of the description' taken together with the accompanying drawings and the claims, by the use of a device which may be adapted for attachment to and for use with etching machines ofthetank type which are already 0 installed and in use, or it may be adapted to incorporation in new machines specially constructed to receive it,

Ih'ave'shownin the accompanying draw- "ings-but one' formof the severalwhich embody the principle of myinvention. Ob-

' 'viously there are other embodiments of-the invention which could be used to illustrate it but the one shown is a simple form which "is preferred for some applications. In Figure 1,1 have shown ageneral view "ofithe' chosen embodiment of my invention in place in an etching" tank and in Figure 2 *I have shown a view on the line AA at right angles to the view in Figure '1'. Figure 3 shows a detail of a portion of the mechanism and Figure 1 shows alternate simplified form lofthemechanism. 7 1 a In Figure 1, 1 represents the acid resistant "tank or receptacle within which the etching V processis carried-out; 2 is the rotatable paddle wheel which picks up the etching fluid and projects it againstthe plate'to be etched;

31s the shelf or ledge extending along one end of the etchingtank and upon which the 5 plate to be etched is commonly placed;'4= is the-slidingv cover of the etching tank by means of, which the opening in the top of the tank. isclosed while the etching operat1on is going on within the tank. These parts are typical ofmany of the'etching machines now in common use. At 5 is shown a plate carrier of acid'resistanthmaterial which is attached by means of a bracket 6 to a sleeve 7 which is slidably mounted on a vertical guide 8, which is carried onabase 9 resting on or fastened to the floor.. At the. top of the vertical guide 8 is ,mounted asheave wheel by means of a suitable bracket l0. The moveable parts just described are conveniently counterbalanced by means of a chain or cord 12, one end of which is attached to the slidable sleeve 7, and after passing over the sheave wheel '11 the other end is attached .to a counterweight 13 which is of weight approximately equal to the combined weight of. thexplate carrier 5,, the bracket ,6, and the sleeve 7. A guide pin 14: fixed to the sleeve 7 and engages a slot 15 in side of the guide 8, which in this case is preferably made cylindricaland hollow. The slot 15 extends vertically along the side of the guide 8 from a point 16 a little belowthe position of'the wardly until its bottom clearsthe top of the etching tank. Fromthis point 17 theflsaid slot is in the form of'a spiral about the guide 8 and extends around said guide one fourth of its circumference, to the point 18. On the innerprojectin'g end of the guidepin 14 is provided a hole 19 forreceiving the chain or cord.12,- which,v afterpassing over the sheave wheel 11,: is attached to the counterweight 13.

Figure 2 shows the same assembly of parts viewed from the paddle wheel end of the etching chamber on the line AA.

Figure 3 shows in detail the construction and arrangement of the guide pin 14 just 7 described. u i

Figure 4 shows'a simplified form of apparatus. which embodies several of the features and accomplishesseveral of'the objects of the guide'pin 14; isomitted. The cord or chain 12'is attached at one end to the sleeve 7 at the point 1d and after passing up and tiger the'sheave 11 is attached to the weight Having described the construction I will now describe the operation of my invention. I will omit the lesser details of the operation of the etching machine itself since this forms no part of my invention and is well understood by those familiar with the art. it is important, however, to insure a proper understanding of the novelty and convenience to the etcher of my invention, to describe the placing of the plate to be etched in osition in the etching machine and the wit drawing of it for inspection during the progress of the operationot etching and at its completion. 1n etching machines out the type now connnonly used this is accomplished by moving the sliding cover a so as to openaportion of the top of the etching tank 1. The operator then leans over the tank and places the plate to be etched by hand on the ledge 3. in doing so he exposes himself to the gases and iuines which arise from the opening in the top of the tank and breathes the noxious and irritating gases into his lungs. His hand, with which he places the plate upon the ledge 25, is exposed to the stronger i umes within the tank and to the corrosive acids dripping from the top and down the sides of the tank. But this is not the severest exposure to which the operator is submitted while etching with the common typecof machine. \Vhen the able conditions. '1

plate is partly etched it must be frequently cxaminedby the operator, and it must be turned to a new position on its support so that an even etch will be secured. At each of these examinations and turnings the operator. leans over the open tank, breathes the fumes, which are extremely obnoxious, and handles a plate wet with corrosive etching fluid and otherwise is exposed to gases, spray and fluid. WVith iny novel device the operator is not subiected to these objectionoremove a plate from the tank for examination or for turning or when the etching process is completed, the operator takes hold of the sleeve 7 and, assisted by the action of the counterweight 13, raises the plate carrier 5 to the upper limit of its travel. In this position the lower edge of the plate carrier 5 will be clear of the top oi: the tank 1, and may be rotated about the vertical guide 8 to bring the plate being etched into convenient position for examination by the operator. VVith the plain form of vertical guide 8 shown in Figure i the operator rotates the plate carrier by hand to bring the plate being etched into the desired position but with the form oi guide shown in Figures 1 and 2thc plate carrier 5 is automatically rotated about the vertical guide 8 as the plate carrier approaches the upper limit of its travel.

mechanical printing When the bottom of the plate carrier is raised to a point slightly above the to) oi the etching tank the guide pin 14 will rave traveled upward along the straight vertical slot 15 to the point 17. As the slot at this point changes its direction and extends u wardly in a spiral course around the gui e 8 through an angle of 90, the guide pin 14 i pin let has reached the top of the slot at the point 18. The plate being etched will then y have. been removed from the etchingposition within the etching tank and moved up and rotated into a position most convenient for examination by the etchcr, without the ctcher having touched any portion of the plate or apparatus which is wet with the etching fluid. Nor has the ctcher been obliged to put his hand within the etching tank filled with corrosive and skin irritating tumes. breathed the noxious fumes arisin therefrom. The reversal of the above (fescribed operation place the plate to be etched back in the etching tank with like freedom from Nor has be bent over the tank or exposure of the etcher to the fumeswithin a the tank. Should it be desired to rotate the plate carrier through an angle greater than 90 at the upper-portion of its travel, the a spiral portion of the slot 15 may be extended around the vertical guide 8 to give any desired angle of rotation.

Etching machines of the tank type described and shown in the drawings are in common use butso far as I am aware they all possess the disadvantages and the discomforts described above an my novel improvement entirely overcomes. Having described the principle of 111 improvement and two of its several em 0diroduce '1 a which nients, I will now state what I claim to be new and novel and for which I desire to secure Letters Patent:

1. An improvement inetching machines for etching photo-mechanical printing plates comprising in combination a holder for the i a plate to be etched slidably mounted on a vertical guide, a counterweight arranged to counterbalance the weight of the plate holder and its slidalole mountings substantially as described.

2. An attachment for use with etching machines of the tank type for etching photop ates comprising in combination a holder for the plate to be for-etching photo-mechanical rinting plates comprising in combination a older for the etched slidably mounted on a vertical guide,

plate to be etched, means rigidly connecting said holder with a sliding member moveable along a vertical guide, means attached to said sliding member engaging a slot or groove in said guide whereby the movement of said sliding member is directed along sald guide. a I

4. An etching machine for. etching photo- "mechanical printing plates comprisin in combinationa chamber forthe etc-hing uid,

a rotatable spray-produclng member, and a carrier for the plate to be'etched slidably mounted on a guide whereby the plate may be entered into and withdrawn from the etching chamber.

5. An etching machine for etching photos mechanical printing plates 'comprisin .in combination a chamber for the etching uid, a rotatable spray-producing member, and a counterweighted carrier for the plate to be etched slidablymounted on a vertical guide whereby the plate may be entered into and withdrawn from the etching chamber.

, 6. An etching machine foretching photomechanical printing plates comprisin in combination a chamber for the etching 51nd. a rotatable spray-producing member and a carrier for the plate to be etched slidably mounted on a guide having means for directing the vertical and rotative motion of the carrier whereby the plate may be entered into and withdrawn from the etching cham-' her.

7. An etching machine for etching photomechanical printing plates com risin in combination a chamber for the etc ing uid, a rotatable spray-producing member, and a counterweighted carrierfor the plate to be etched slidably mounted, on a guide having means for directing the vertical and rotative motion of the carrier whereby the plate may be entered into and' withdrawn from the etching chamber.

, Signedat Douglaston, in the county of Queens, city and State of New York, this 14th day of December, A. D. 1926.

FRANK T. POWERS. 

